1. Technical Field
This disclosure relates to a structural fastener and components thereof and, in particular, to a captive structural fastener with an integral hold-out feature and components thereof.
2. Related Cases
Benefit is hereby claimed under 35 U.S.C. § 120 of the filing date of commonly owned and co-pending U.S. patent application Ser. No. 10/137,011 filed on May 2, 2002, which is incorporated herein by reference in its entirety.
3. Background
A variety of fasteners or fastener assemblies (hereinafter “fasteners”) are known for attaching a panel to a sub-structure. Such fasteners are typically designed for use in high stress environments, such as to protect aircraft access panels, and when used in such environments, are referred to as “structural” fasteners. Structural fasteners are used to maintain secure attachment of the panel to the sub-structure panel during conditions of excessive vibration and high loads applied to the panel during flight.
“Captive” fasteners include studs or screws that remain captive in the stud assembly when the panel is removed from the sub-structure. When panels in which captive fasteners have been installed are removed from the sub-structure, the studs remain with the cover, maintaining the position of the studs relative to the panel and eliminating the problem of stud loss or displacement.
Some captive fasteners have “hold-out” features that involve the use of a hollow stud in which a separate retaining mechanism is positioned. These types of studs are difficult to manufacture and assemble, and can be problematic in use because “foreign object debris” (FOD) accumulates in the hollow portion of the stud, over time leading to eventual failure of the fastener.
Captive fasteners are prone to failure for other reasons as well. One reason is due to the fact that other fasteners have reduced life due to breakage of retaining rings, as well as other components of the assemblies. When the retaining ring breaks, depending on the design of the fastener, it often may result in the screw or stud falling out of the assembly, defeating the purpose of using a “captive” fastener assembly.
Of course, breakage of any part of the fasteners may lead to failure and, in addition, may lead to failure of other fasteners if the debris travels and is accumulated in other, un-broken fasteners. Also, this debris could short-out electronic components associated with the aircraft.
Thus, a need in the art exists for a captive structural fastener that reduces or eliminates the problem of foreign object debris.